Passage 1.27.6
ἀρχαῖα· καί σφισιν ἀπετάκη μὲν οὐδέν, μελάντερα δὲ καὶ πληγὴν ἐνεγκεῖν ἐστιν ἀσθενέστερα· ἐπέλαβε γὰρ καὶ ταῦτα ἡ φλόξ, ὅτε ἐσβεβηκότων ἐς τὰς ναῦς Ἀθηναίων βασιλεὺς εἷλεν ἔρημον τῶν ἐν ἡλικίᾳ τὴν πόλιν. ἔστι δὲ συός τε θήρα, περὶ οὗ σαφὲς οὐδὲν οἶδα εἰ τοῦ Καλυδωνίου, καὶ Κύκνος Ἡρακλεῖ μαχόμενος· τοῦτον τὸν Κύκνον φασὶν ἄλλους τε φονεῦσαι καὶ Λύκον Θρᾷκα προτεθέντων σφίσι μονομαχίας ἄθλων, περὶ δὲ τὸν ποταμὸν τὸν Πηνειὸν ἀπέθανεν ὑφʼ Ἡρακλέους.
These sculptures are very ancient, and although none of them melted, they became darker in color and weaker to withstand blows. For these too were touched by flames when the Persian king captured a city deserted by all those of military age, since the Athenians had already embarked upon their ships. Among them is depicted a boar hunt, about which I do not know for sure whether it represents the Calydonian one. Also shown is Cycnus fighting against Heracles. This Cycnus, it is said, killed various other men, including Lycus the Thracian, competing in contests of single combat set before them, but near the river Peneius he himself was slain by Heracles.